The self-doping effect is supported by first-principles band structure
calculations [1]}, where the Nd \(5d\)  orbitals in NdNiO\(_{2} \)  are found to hybridize with the Ni \(3d\)  orbitals and give rise to
small electron pockets in the Brillouin zone. Thus, we have a small number
of Nd-5\(d\)  conduction electrons. This is actually supported by experiment.
At high temperatures, the Hall coefficient is dominated by conduction
electrons giving \(R_H\approx -4\times 10^{-3}\,\) cm\(^{3}\)  C\(^{-1}\) 
for NdNiO\(_{2}\)  and \(-3\times 10^{-3}\,\) cm\(^{3}\)  C\(^{-1}\)  for LaNiO\(_{2}\) . By contrast, in typical heavy fermion metals such as Ce\(M\) In\(_{5}\)  (\(M\) = Co, Rh, Ir) , we have \(R_{H}\approx -3.5\times 10^{-4}\,\) cm\(^{3}\)  C\(^{-1}\)  at high temperatures [2]}. The larger and
negative values of the Hall coefficient implies that there are only a few
percent of electron-like carriers per unit cell in NdNiO\(_{2}\)  and LaNiO\(_{2}\) .
